[source] ramips: fix fixseama call on first boot

[LEDE Commits]

neoraider pushed a commit to source.git, branch master:
https://git.lede-project.org/?p=source.git;a=commitdiff;h=fa9811814a97fbd0d01cce5e7faf955e7e2c407c

commit fa9811814a97fbd0d01cce5e7faf955e7e2c407c
Author: Matthias Schiffer <mschiffer at universe-factory.net>
AuthorDate: Thu Jun 30 15:50:11 2016 +0200

    ramips: fix fixseama call on first boot
    
    Commit "kernel: mtdsplit: calculate kernel partition precisely for Seama"
    changed the kernel partition to only contain the kernel itself and not
    the Seama header. Adjust the fixseama call to match what is used on
    brcm53xx.
    
    This fixes failing to boot a second time after flashing the factory image
    on the affected devices.
    
    Signed-off-by: Matthias Schiffer <mschiffer at universe-factory.net>
    Reviewed-by: Jo-Philipp Wich <jo at mein.io>
---
 target/linux/ramips/base-files/etc/uci-defaults/09_fix-seama-header | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/target/linux/ramips/base-files/etc/uci-defaults/09_fix-seama-header b/target/linux/ramips/base-files/etc/uci-defaults/09_fix-seama-header
index 35167f1..7a0a325 100644
--- a/target/linux/ramips/base-files/etc/uci-defaults/09_fix-seama-header
+++ b/target/linux/ramips/base-files/etc/uci-defaults/09_fix-seama-header
@@ -6,9 +6,9 @@
 . /lib/ramips.sh
 
 fix_seama_header() {
-	local part=$1
+	local kernel_size=$(sed -n 's/mtd[0-9]*: \([0-9a-f]*\).*"kernel".*/\1/p' /proc/mtd)
 
-	mtd fixseama $part
+	[ "$kernel_size" ] && mtd -c 0x$kernel_size fixseama firmware
 }
 
 board=$(ramips_board_name)
@@ -17,6 +17,6 @@ case "$board" in
 cy-swr1100 | \
 dir-645 | \
 dir-860l-b1)
-	fix_seama_header kernel
+	fix_seama_header
 	;;
 esac